The invention relates to leaf-spring assemblies for automobile suspension systems and the like.
German Patent Document 2,349,381 discloses known leaf-spring assemblies consisting of a main spring leaf having integrally formed spring eyes and a supporting spring leaf reaching beneath this main spring leaf. The two spring leaves are connected in their center area by a center bolt and are protected close to their end against expanding in the vertical direction (fanning-out) in particular by spring clips. In addition, the supporting spring leaf has a rolled-over portion overlapping the eye of the main spring leaf in order to maintain the guidance of the axle via the leaf-spring assembly in the event of the main spring leaf fracturing. Furthermore, in the known construction, a rib guide extending in the longitudinal direction of the spring is provided between the main spring leaf and the supporting spring leaf in the end area of the spring, and in fact approximately in the overlap area relative to the spring eye, which rib guide serves as protection against lateral shifting (splaying) of the spring leaves of the spring assembly. The rib guide is formed by the additional spring leaf being designed to be narrower than the main spring leaf and by the main spring leaf being provided with rib guides in the area projecting laterally beyond the additional spring leaf, between which rib guides the supporting spring leaf lies. The distance between the rolled-over portion and the spring eye of the main spring leaf is selected in such a way that assembly of the spring leaves is possible in the relieved state and said distance is thereby also large enough to virtually eliminate contact between the rolled-over portion and the spring eye.
In this known construction, as in similar further embodiments having protection against splaying by rib guides running in the longitudinal direction of the spring (Austrian Patent 176,131), spring clips, as already mentioned, are used, which means additional expenditure.
An object of the invention is to design a leaf-spring assembly of the said type having more than two leaf springs in such a way that spring clips can be dispensed with.
This object is achieved according to certain preferred embodiments of the invention in a leaf-spring assembly wherein at least one intermediate spring leaf lies between a main spring leaf and a supporting spring leaf such that the main spring leaf, the intermediate spring leaf and the supporting spring leaf are held together in the vertical direction via the supporting spring leaf, and the intermediate spring leaf and supporting spring leaf are protected against splaying by a rib guide, and wherein, in the vertical extent of the rib guide, the clearance of movement between the spring eye of the main spring leaf and the rolled-over portion of the supporting spring leaf in the direction of vertical or protruding height of the rib guide is less than the overlap height of the rib guide with respect to the adjacent intermediate spring leaf.
In a leaf-spring assembly constructed in this way, the main spring leaf, the intermediate spring leaf and the supporting spring leaf have roughly the same length, and furthermore protection against splaying is provided by rib guides between intermediate spring leaf and supporting spring leaf, and the requisite safeguard against fanning-out, which at the same time would permit splaying, is obtained owing to the fact that the rolled-over portion of the supporting spring leaf has clearance in the vertical direction relative to the spring eye, which clearance is less than the guide height of the rib guides. In this construction, therefore, the intermediate spring leaves are also essentially fixed in the vertical direction relative to the main spring leaf by the supporting spring leaf.
The requisite longitudinal displaceability between the individual spring leaves of the assembly as well as frictional relationships which are favorable even under difficult conditions are ensured by the guide ribs being lower in their height than the depth of the location grooves, which in addition are also longer than the guide ribs.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.